sin(x)^2+cos(x)^2 = 1 on different calcs

[Albert Chan]

Hi, Csaba Tizedes

You got a big 0 for sums because of another Casio "feature".
For example, below test from my Casio-FX115MS, which claimed 12 internal digits.

9999999999 ->M (M has full 10 digits)

M + 0.94 - M ==> 0.94
M + 0.95 - M ==> 1 ???

M + 0.10 - M ==> 0.10
M + 0.09 - M ==> 0 ???

So, sin(X)^2 + cos(X)^2 get rounded to exactly 1 (Almost always)
This, on top of small difference set-to-zero "feature"

Edit: round-up feature only for M with all 9s. Do not know why ...